N.J. Stat. § 2A:30-1: Liability of plaintiff upon discontinuance without leave

If the plaintiff in any action for the recovery of a penalty, not wholly appropriated to the use of the plaintiff, settles with the defendant, and discontinues the action without leave of the court, the plaintiff shall be liable to the state or to a political subdivision of the state, or to any other person, for so much of the penalty as would have accrued to the state or to the political subdivision, or to such other person, if judgment had been taken against the defendant.

L.1951 (1st SS), c.344.